Global Sources of Local Pollution: An Assessment of Long-Range Transport of Key Air Pollutants to and from the United States (2009)

Recent advances in atmospheric monitoring and modeling have helped confirm that air pollution can be transported aloft across oceans and continents, affecting air quality and ecosystems far from the original pollution sources. It is currently quite difficult to quantify this transport or its impacts, but there is evidence that in some cases, the influence of long-range pollution transport can be 'significant' from a regulatory and public health perspective. To help policymakers and air quality managers better understand these issues, the National Research Council was asked to assess long-range atmospheric transport of four key types of pollutants: ozone, particulate matter, mercury, and persistent organic pollutants. The report, Global Sources of Local Pollution, assesses the current state of knowledge, and recommends the creation of an integrated pollution source attribution system. This system will help us to better quantify and predict future impacts of transported pollution, and design effective response strategies.

Dr. W. Wallace McMillan is an Associate Professor of Physics at the University of Maryland, Baltimore County. His research has focused on global, regional, and local measurements of pollution. As a member of the science team for NASA's Aqua satellite-based Atmospheric InfraRed Sounder (AIRS), he has worked with infrared imagery that affords a unique look at global pollution flows. This short video showing plumes of carbon monoxide moving through the atmosphere illustrates the transport of pollution around the globe. Obtained using the AIRS, these observations track carbon monoxide at about 5.5 kilometers above the surface of the Earth. Emissions of carbon monoxide from large fires and from large urban and industrial areas, such as northeastern China, can be seen as they move along with weather fronts. The animation you see was assembled by Ed Olsen at NASA's Jet Propulsion Laboratory, and we thank the AIRS project office and the entire AIRS team and NASA for their support in bringing you these images.

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In satellite images we can watch as plumes of air pollution drift and flow between continents and across oceans. The figures below demonstrate the global reach of atmospheric pollutants.

Major atmospheric pathways, represented here by arrows, can transport pollution around the globe within weeks. Analysis of trajectory studies and other sources estimates that the timescale of pollution transport is as follows: (A) Midlatitudes to Arctic: 1-4 weeks. (B) Midlatitudes to Tropics: 1-2 months. (C) Northern Hemisphere to Southern Hemisphere: ~1 year (D) North America to Western Europe: 3-13 days (E) Northern Africa to North America: 1-2 weeks. (F) Eastern Europe to Asia: 1-2 weeks. (G) Eastern Asia to North America: 4-17 days.

Average carbon monoxide abundance in the free troposphere observed by the Terra/MOPITT satellite during an 8-day period in July 2004. Plumes of anthropogenic carbon monoxide pollution can be seen leaving Asia and crossing the Pacific Ocean, and plumes of pollution from Alaskan and Canadian forest fires can be seen crossing North America and the Atlantic Ocean towards Europe. Credit: D. Edwards, NCAR

Links

The following Web sites offer valuable background information and key source material from international legislation and research on global pollution flows.

UN Economic Commission for Europe Task Force on Hemispheric Transport of Air Pollution
Convention on Long-range Transboundary Air Pollution

UN Environment Programme Global Partnership of Atmospheric Mercury Transport and Fate Research

Stockholm Convention on Persistent Organic Pollutants

U.S. Environmental Protection Agency - International Programs

NOAA Research:
Tropospheric Ozone and Air Quality Aerosols: Climate and Air Quality

National Park Service - Western Airborne Contaminants Assessment Project

NASA Sites:
NASA Satellite Tracks Hazardous Smoke and Smog Partnership

NASA - Measurement of Atmospheric Composition in the Ultraviolet Region

NASA's Terra Satellite Tracks Global Pollution

The Intercontinental Chemical Transport Experiment (INTEX)-B Campaign
http://www-air.larc.nasa.gov/missions/intex-b/intexb.html

http://www.espo.nasa.gov/intex-b/index.html